DFSCGxxx member of the IMS PROCLIB data set

All of the parameters that are valid in the DFSCGxxx member of the IMS PROCLIB data set are valid in the DFSDFxxx member of the IMS PROCLIB data set. If you specify values in both the DFSCGxxx member of the IMS PROCLIB data set and the CSL section of the DFSDFxxx member of the IMS PROCLIB data set, the values specified in the DFSCGxxx member override the values specified in the DFSDFxxx member.

The suffix for DFSCGxxx, xxx, is specified on the CSLG= parameter. All IMSplex members (OM, RM, SCI, IMS, and others) that are in the same IMSplex sharing group, sharing either databases or message queues, must specify the same values.

Environments

The DFSCGxxx member of the IMS PROCLIB data set can be used in the IMS DB/DC and DBCTL environments.

Syntax

You can use the IMS Syntax Checker to modify this member of the IMS PROCLIB data set.

Usage

A DFSCGxxx member consists of one or more fixed-length character records (the configuration data set can be of any LRECL greater than eight, but it must be fixed record format). The rightmost-eight columns are ignored but can be used for sequence numbers or any other notation. Keyword parameters can be coded in the remaining columns in free format, and can contain leading and trailing blanks. You can specify multiple keywords in each record; use commas or spaces to delimit keywords. Statements that begin with a “*” or “#” in column 1 are comment lines and are ignored. Additionally, comments can be included anywhere within a statement by enclosing them between “ /* ”and “*/”, for example, /* PROCLIB comments */. Values that are coded in this member of the IMS PROCLIB data set are case-sensitive. In general, use uppercase for all parameters.

For installations that do not require Resource Manager services, the DFSCGxxx member of the IMS PROCLIB data set includes parameters (RMENV, OMPROC, and SCIPROC) for specifying that a Resource Manager environment is not required. These parameters are useful if you do not use shared queues or a sysplex, but you would like to issue IMS type-1 and type-2 commands through the OM API.

The DFSCGxxx parameters can also be specified on the DFSDFxxx member of the IMS PROCLIB data set.

Important: When RMENV=N and OLC=GLOBAL is specified, ensure that no other IMS attempts to use the same OLCSTAT data set. If another IMS uses the same OLCSTAT data set, or if the OLCSTAT data set utility (DFSUOLC0) is used to initialize the data set for another member, an additional IMSID is added to the OLCSTAT data set. If this occurs and IMS (running with RMENV=N and OLC=GLOBAL specified) attempts to initiate an online change by issuing the INIT | TERM OLC command, the command is rejected because an IMSID other than the one executing the command resides in the OLCSTAT data set. The OLCSTAT data set must then be corrected before an INIT | TERM OLC can complete successfully.

Parameters

ACBSHR=

Specifies whether this IMS system shares a common set of application control blocks (ACBs) with other IMS systems in an IMSplex. The ACBSHR= parameter determines whether changes to a set of ACBs must be coordinated across multiple IMS systems.

The shared set of ACBs can be in either ACB libraries or, if the IMS management of ACBs is enabled, a shared IMS catalog.

The ACBSHR parameter can be specified in both the DFSCGxxx member and the COMMON_SERVICE_LAYER section of the DFSDFxxx member in the IMS PROCLIB data set. If ACBSHR is specified in both members, IMS uses the ACBSHR value that is specified in the DFSCGxxx member of the IMS PROCLIB data set.

In an environment that uses ACB libraries, each IMS system that shares an OLCSTAT data set must have the same value for ACBSHR=. If the ACBSHR= values are not the same, the INIT OLC PREPARE TYPE(ACBMBR) command is rejected.

When the IMS management of ACBs is enabled by ACBMGMT=CATALOG, the ACBSHR parameter alone determines which IMS systems are included in the global coordination of ACB changes. ACB changes are activated by the IMPORT DEFN SOURCE(CATALOG) command. The Online Change process is not used for ACB changes when ACBMGMT=CATALOG.

Y

Specifies that the set of ACBs that is used by this IMS system is shared by other IMS systems. Any changes to the shared set of ACBs must be coordinated among the sharing IMS systems.

If ACB libraries are used and OLC=GLOBAL, the global Online Change process requires both the CSL Resource Manager (RM) and an OLCSTAT data set to coordinate changes to ACBs among the online IMS systems in the IMSplex.

If the IMS management of ACBs is enabled, RM is required to coordinate ACB changes globally among all online IMS systems that specify ACBSHR=Y in an IMSplex. The OLC process is not used, so the OLC= parameter and the OLCSTAT data set do not apply.

When IMS manages ACBs, the ACBSHR= specification of each IMS system in the IMSplex determines whether the IMS system is included in the global coordination of ACB changes.

If ACBSHR=Y is specified in the command master when the IMPORT DEFN SOURCE(CATALOG) command is issued, the IMPORT DEFN command is routed to and processed by all IMS systems in the same IMSplex that also specify ACBSHR=Y, even if they are not specified on the ROUTE parameter in TSO SPOC. If any systems that specify ACBSHR=N other than the command master are specified on the ROUTE parameter, those IMS systems also attempt to process the IMPORT DEFN command, but processing is asynchronous and succeeds only if those systems have pending ACB changes in a separate IMS catalog.

If ACBSHR=Y is specified for IMS systems in a sysplex data sharing environment, you must specify PDSESHARING(EXTENDED) in the IGDSMSxx member of SYS1.PARMLIB for each z/OS® system in the sysplex.

N

Specifies that this IMS system uses its own dedicated set of ACBs.

If ACBSHR=N is specified in the command master when the IMPORT DEFN SOURCE(CATALOG) command is issued, the IMPORT DEFN command is processed locally only, unless other IMS systems that also specify ACBSHR=N are specified on the ROUTE parameter in TSO SPOC. If other IMS systems also process the IMPORT DEFN command, but they do so asynchronously and only if they have pending ACB changes in their own IMS catalog.

CMDSEC=

Specifies whether IMS should perform security checking on commands that are routed from OM, and if so, whether RACF® or the Command Authorization exit routine (or both) should be used. If IMS performs the security checking on commands, the CMDSEC keyword also specifies whether RACF, the IMS Command Authorization exit routine (DFSCCMD0), or both should be used. This option applies only to IMS type-1 commands that can be issued through the OM API.

For type-2 commands (that are only allowed through the OM API, not allowed from the IMS master terminal), all security checking is performed by OM and is controlled by the CMDSEC= parameter on the OM startup JCL or on the OM initialization member of the IMS PROCLIB data set (CSLOIxxx).

Recommendation: Use OM command security instead of IMS security. By allowing OM to perform the security checks, commands which fail security authorization are not routed to IMS, which reduces processing overhead and network traffic. When IMS command security is used, you must ensure that all IMS systems use the same security profiles and user exits. If IMS systems in the same IMSplex use different security rules, the results of command security checking may be unpredictable.

A

Specifies that both RACF and DFSCCMD0 are to be called (options E and R). RACF is called first. Then the security authorization facility (SAF) return code, RACF return code, and RACF reason code are passed to DFSCCMD0.

E

Specifies that the Command Authorization exit routine is to be called for command authorization.

N

Specifies that no authorization checking is to be done. Security checking can still be performed by OM depending on the specification of the OM CMDSEC= parameter.

R

Specifies that RACF is to be called for command authorization.

DBQUIESCETO=

The amount of time, in seconds, that the QUIESCE command waits for currently running applications to commit before the QUIESCE command is aborted. This value applies only when the quiesce function is initiated. The actual time required for the QUIESCE command varies and might exceed this timeout value. The default value is 30 seconds. sss must be a non-zero value 1 - 999. You can also specify this timeout value in the COMMON_SERVICE_LAYER section of the DFSDFxxx member of the IMS PROCLIB data set, or override the value using the appropriate UPDATE command for the resource type, for example, UPDATE DATAGRP NAME(name) START(QUIESCE) SET(TIMEOUT(10)).

GBL_SERIAL_PGM=Y | N

Specifies whether (Y) or not (N) the sysplex serial program management feature of IMS is active. The default is Yes.

This parameter can be specified in both the DFSCGxxx and DFSDFxxx members of the IMS PROCLIB data set. If it is specified in both members, IMS uses the GBL_SERIAL_PGM value that is specified in the DFSCGxxx member.

IMSPLEX=

Specifies a one- to five-character identifier. IMS appends this identifier to CSL to create the IMSplex group name. All IMSplex members (OM, RM, IMS, CQS) that are in the same IMSplex sharing group sharing either databases or message queues must specify the same identifier. IMS has no way to enforce this; the user is responsible for ensuring that the IMSplex name is correctly specified. The same identifier must also be used for the IMSplex= parameter in the CSLSIxxx, CSLOIxxx, CSLRIxxx, and CQSIPxxx members of the IMS PROCLIB data set.

When RMENV=N, IMSPLEX= specifies a one- to five-character name of the IMSplex that OM, SCI, and the IMS control regions join. This IMSplex is simply a grouping of all address spaces that are managed by one or more OMs.

This parameter is required.

LEOPT=Y | N

Specifies whether IMS should allow IBM® Language Environment® for z/OS (LE) dynamic runtime parameter overrides.

MODBLKS=

Specifies whether resources in the IMS.MODBLKS data set are defined dynamically or by online change. These resources include databases, programs, routing codes, and transactions. This attribute can only be changed on an IMS cold start. If the value is changed for the next IMS warm or emergency restart, IMS restart terminates, and abend U0168 is issued.

DYN

Enables dynamic definition for resources in the IMS.MODBLKS data set. Resource definitions can be dynamically added, changed, or deleted by using online commands, including CREATE, DELETE, and UPDATE. Online change for resources in the IMS.MODBLKS data set that is initiated by a /MODIFY PREPARE MODBLKS or INITIATE OLC PHASE(PREPARE) TYPE(MODBLKS) command is not allowed.

OLC

Enables online change for resources in the IMS.MODBLKS data set. Resource definitions can be added, changed, or deleted by using online change. Online change commands for resources in the IMS.MODBLKS data set include /MODIFY PREPARE MODBLKS or INITIATE OLC PHASE(PREPARE) TYPE(MODBLKS). When MODBLKS=OLC, UPDATE commands that update runtime values (such as a transaction class) are permitted. This is the default.

ODBMSECURE=

Specifies whether IMS performs security checking on the PSB resource for an ODBM thread at the time of the allocate PSB (APSB) request. The RACF general resource class (RCLASS), AIMS or Axxxxxxx (where xxxxxxx is the value specified on the RCLASS= initialization EXEC parameter), is used for PSB resource checking.

Specifying any value other than ODBMSECURE=I overrides the ISIS= and ODBASE= parameters for APSB requests from an ODBM connector.

I

Ignore. Specifies that the ODBMSECURE= parameter is to be ignored. I is the default.

N

None. Specifies that no security checking is to be performed for APSB requests from an ODBM thread. Specifying ODBMSECURE=N overrides both the ISIS= and ODBASE= parameters.

A

All. Specifies that both RACF and the IMS RASE user exit routine are to be called (options E and R) for PSB authorization. RACF is called first. The SAF return code and the RACF return and reason codes are passed to the IMS RASE user exit routine.

E

Exit. Specifies that the IMS RASE user exit routine is to be called for PSB authorization.

R

RACF. Specifies that RACF is to be called for PSB authorization by using the AIMS or Axxxxxxx general resource class.

NORSCCC=()

Resource consistency checking is no longer performed for ACBLIB, FMTLIB, and MODBLKS libraries, regardless of whether there is a resource structure or if values are specified on NORSCCC. The NORSCCC keyword is supported for compatibility, but its values are ignored.

OLC=LOCAL | GLOBAL

Specifies the scope of the online change. OLC=LOCAL means that the online change applies locally to each IMS. Local online change is prepared and committed by using the /MODIFY PREPARE and /MODIFY COMMIT commands on each local IMS. The local online changes must be manually coordinated across an IMSplex. OLC=GLOBAL means that the online change is coordinated across the IMSplex; ACBLIB member OLC requires OLC=GLOBAL. Global online change is prepared and committed by using the INITIATE OLC command. If global online change is enabled and a resource structure is defined, the MODBLKS, FORMAT, and ACBLIB data sets must be consistent across the IMSplex, unless resource consistency checking is omitted by the NORSCCC keyword.

When the IMS management of ACBs is enabled, the OLC parameter does not apply to changes made to ACBs. Instead, the value of the ACBSHR= parameter determines whether IMS activates ACBs only locally or coordinates the activation globally when the IMPORT DEFN SOURCE(CATALOG) command is issued.

OLCSTAT=

Specifies the 1 - 44 character data set name of the OLCSTAT data set. OLCSTAT is ignored if OLC=LOCAL is specified. OLCSTAT is required if OLC=GLOBAL is defined. The OLCSTAT data set is a cataloged BSAM data set that contains global online change information and status. The data set name is used to dynamically allocate the data set when an IMS initialized, restarts, or is master of an online change phase.

All IMS systems in an IMSplex must refer to the same physical OLCSTAT data set. If a resource structure is defined to the IMSplex, IMS ensures that the OLCSTAT data set name is defined consistently for the IMSplex. If the OLCSTAT data set name definition is not consistent with the OLCSTAT defined to other IMS systems in the IMSplex, IMS initialization fails.

When the IMS management of ACBs is enabled, the OLCSTAT parameter does not apply to the activation of new or modified ACBs in online IMS systems.

RMENV=Y | N

Indicates whether (Y) or not (N) IMS requires an RM environment.

Y

Indicates that IMS requires an RM environment in order to use Resource Manager services. IMS initialization does not complete until IMS successfully registers with RM. This is the default.

N

Indicates that IMS does not require an RM environment and does not use Resource Manager services. IMS does not attempt to register with RM even if an RM address space is active. When RMENV=N, you do not need to define or start an RM address space. IMS commands and functions that require RM are not available in this environment.

When the IMS management of ACBs is enabled, a specification of RMENV=N limits the activation of ACB changes to the local IMS system. If the ACBs are shared by other IMS systems, as indicated by ACBSHR=Y, you must coordinate the activation of ACBs in the other systems separately.

When RMENV=N, online change is as follows:

• If OLC=LOCAL, use the /MODIFY command to initiate online change. The MODSTAT data set must be defined.
• If OLC=GLOBAL, use the INIT OLC command to initiate online change. The OLCSTAT data set must be defined; however, it cannot be shared between IMS systems.

You can change the value of RMENV= across IMS warm or cold starts.

RMPROC=

Specifies the one- to eight-character name of the member of the IMS PROCLIB data set that contains the procedure for the RM address space. This parameter is optional.

IMS does not start the RM address space specified by this parameter if another RM address space is already active in the IMSplex during IMS initialization.

If RMPROC= is not specified, start the RM address space before starting IMS. This start sequence can be performed through an automation program or by another IMS control region.

OMPROC=

Specifies the one- to eight-character name of the member of the IMS PROCLIB data set that contains the procedure for the OM address space. This parameter is optional.

IMS does not start the OM address space specified by this parameter if another OM address space is already active in the IMSplex during IMS initialization.

If OMPROC= is not specified, start the OM address space before starting IMS. This start sequence can be performed through an automation program or by another IMS control region.

PLEXPARM=()

PLEXPARM is optional. If you do not specify it, either the default value or a NULL value is used. Refer to the specific subparameter to determine whether the default or NULL value is used.

The PLEXPARM parameter defines how global status is maintained for resources in an IMSplex. An IMS system that is initialized in an IMSplex checks to see if a global PLEXPARM entry exists in the RM resource structure. If the entry exists, the IMS system uses the values. If no entry exists, the initializing IMS writes its resource definition values to the RM resource structure global PLEXPARM entry. Any IMS system that initializes in that IMSplex after that uses the values stored by the first IMS system. If the subsequent IMS system has PLEXPARM values that are different from the values in the global PLEXPARM entry, message DFS3425I is issued, and values from the global PLEXPARM entry are used.

To view the current PLEXPARM values, use the QUERY IMS command. To update PLEXPARM values, use the UPDATE IMS command.

If an IMS system is running in an IMSplex that does not include an RM, or the RM in the IMSplex does not use a resource structure, the PLEXPARM parameter is ignored. No message is issued indicating that the parameter is ignored. All PLEXPARM values are set to no (N).

In an FDBR system, the PLEXPARM parameter is ignored. No message is issued indicating that the parameter is ignored. All PLEXPARM values are set to no (N). However, an FDBR system and an XRF alternate system do maintain global PLEXPARM values internally. You can use the QUERY IMS SHOW(PLEXPARM) command to display PLEXPARM values in an FDBR or XRF alternate system.

GSTSDB=

Specifies how global status for databases is kept in the IMSplex.

N

No global status is maintained for databases resources in the RM. This is the default value for DB/DC and DBCTL regions.

Y

Global status for databases is maintained in the RM.

null

No global status is maintained for databases resources in the RM. This is the default value for DCCTL regions.

A DCCTL system that initializes this value in the global PLEXPARM entry writes a null value. If a DB/DC or DBCTL system later joins that IMSplex, that system updates the GSTSDB value in the global PLEXPARM entry with the value from its PLEXPARM initialization parameter.

GSTSAREA=

Specifies how global status for DEDB areas is kept in the IMSplex.

N

No global status is maintained for DEDB area resources in the RM. This is the default value for DB/DC and DBCTL regions.

Y

Global status for DEDB areas is maintained in the RM.

null

No global status is maintained for DEDB area resources in the RM. This is the default value for DCCTL regions.

A DCCTL system that initializes this value in the global PLEXPARM entry writes a null value. If a DB/DC or DBCTL system later joins that IMSplex, that system updates the GSTSDB value in the global PLEXPARM entry with the value from its PLEXPARM initialization parameter.

GSTSTRAN=

Specifies how global status for transactions is kept in the IMSplex.

N

No global status is maintained for transaction resources in the RM. This is the default value for DB/DC and DCCTL regions.

Y

Global status for transactions is maintained in the RM.

null

No global status is maintained for transaction resources in the RM. This is the default value for DBCTL regions.

A DBCTL system that initializes this value in the global PLEXPARM entry writes a null value. If a DB/DC or DCCTL system later joins that IMSplex, that system updates the GSTSDB value in the global PLEXPARM entry with the value from its PLEXPARM initialization parameter.

SCIPROC=

Specifies the one- to eight-character name of the member of the IMS PROCLIB data set that contains the procedure for the SCI address space. This parameter is optional.

If SCIPROC= is not specified, start the SCI address space before starting IMS. This start sequence can be performed through an automation program or by another IMS control region.

UOM=

Specifies which unsolicited output messages are sent to the Operations Manager:

MTO

Send only unsolicited output messages that are destined for the MTO, unsolicited output messages that are destined for the system console, or both, to OM. This is the default.

NONE

Do not send any unsolicited output messages to OM.

ALL

Send all unsolicited output messages to OM.